No phono here! Strictly digital. I sold my turntable and most of my records years ago. Not that I wouldn't like to try analog again but at my age I find it difficult to justify the money it would cost to get a good analog rig and the records to play on it. Besides, my collection of music, like most collections, is very individual and when I play a 20 year old cd it reminds me of certain times, people and experiences. I couldn't get that from new vinyl no matter how good it would supposedly sound.
I too would really like an all Pass amplification chain but am stuck at the phono stage.
I have the Pearl 2 PCB set, but apparently it may not mate well with the MM cartridge
I use. (Possible overload issue)
I'm not sure what I should do: Charge ahead with the Pearl 2, try to find PCBs and
build the original Pearl or try an MC cartridge.
Dennis
I have the Pearl 2 PCB set, but apparently it may not mate well with the MM cartridge
I use. (Possible overload issue)
I'm not sure what I should do: Charge ahead with the Pearl 2, try to find PCBs and
build the original Pearl or try an MC cartridge.
Dennis
Dear Aleph J builders,
I need some your precious inputs and expertise regarding PSU build for this amp.
Currently in hand, I have 10k uF and 22000 uF capacitors available.
From this thread, 6L6 suggested transformer 300 VA - 500 VA and about 4x15k uF for each rail. That sums up to 60k uF.
For those that already finished Alelph J or have good knowledge on PSU design, Would you please help me pick out one of the following options below for better audio quality results
Btw, i'm using the Universal PSU v3.0 PCB from diystore. Each side of PSU, it has 4 spots for RC caps
1. Use bare minimum for transformer and RC cap: 300 VA transformer, 2x 22000uF and 2 x10000 uF caps (Total of 64000 uF on each side)
2. Use bigger transformer and RC caps: 500 VA or 600 VA at 18V-0-18V with highest output current spec, 4x22000 uF caps on each side (total of 88000 uF)
3. Combination of bigger transformer and small RC cap. 500 VA 18-0-18 and 2x22000uF , 2x10000uF each side.
I've done some readings and some suggest bigger transformer and bigger RC cap is better and some suggest bigger transformer and smaller RC cap is better since it has lower impedance hence lower damping factor. I'm quite confused since I read multiple conflict information online
Q: Does PSU RC capacitors brand name really affect sonic performance ?
Please let me know what you think for these 3 options or you would suggest other alternatives.
What is the appropriate slow blow fuse current rating I can safely use in order to avoid big inrush current from the big caps that could potentially blow up the fuse if I choose one of the 3 options above ?
Thanks,
Tom
I need some your precious inputs and expertise regarding PSU build for this amp.
Currently in hand, I have 10k uF and 22000 uF capacitors available.
From this thread, 6L6 suggested transformer 300 VA - 500 VA and about 4x15k uF for each rail. That sums up to 60k uF.
For those that already finished Alelph J or have good knowledge on PSU design, Would you please help me pick out one of the following options below for better audio quality results
Btw, i'm using the Universal PSU v3.0 PCB from diystore. Each side of PSU, it has 4 spots for RC caps
1. Use bare minimum for transformer and RC cap: 300 VA transformer, 2x 22000uF and 2 x10000 uF caps (Total of 64000 uF on each side)
2. Use bigger transformer and RC caps: 500 VA or 600 VA at 18V-0-18V with highest output current spec, 4x22000 uF caps on each side (total of 88000 uF)
3. Combination of bigger transformer and small RC cap. 500 VA 18-0-18 and 2x22000uF , 2x10000uF each side.
I've done some readings and some suggest bigger transformer and bigger RC cap is better and some suggest bigger transformer and smaller RC cap is better since it has lower impedance hence lower damping factor. I'm quite confused since I read multiple conflict information online
Q: Does PSU RC capacitors brand name really affect sonic performance ?
Please let me know what you think for these 3 options or you would suggest other alternatives.
What is the appropriate slow blow fuse current rating I can safely use in order to avoid big inrush current from the big caps that could potentially blow up the fuse if I choose one of the 3 options above ?
Thanks,
Tom
Hi Tom
I would recommend using a larger transformer than 300va. There seems to be a lack of standards in rating transformers. I used a 400va Antek 20v x2 transformer for my Aleph. With slightly more than the recommended bias it runs pretty warm but not hot. I can vouch for this transformer working well for an Aleph J and will give you close to 24volt rails. I wouldn't go any lower than that size, at least within the Antek line.
With an Aleph J you are usually limited to your heatsink size for turning up the bias. Therefore you really can't get much extra output power from a really large transformer. The 400va Antek also comes with a electrostatic shield and a core band to lower the magnetic field. That will generally mean fewer problems with hum. Some of the larger sizes do not have these features so that is also something to consider.
As far as capacitors go, more is better up to a point. Because an Aleph is single ended you can't get the large peak output currents you will get with a push pull amp like an F5. So, the cap setup recommended by 6L6 is certainly enough for starters. If you think you may want more then leave space in the chassis for more caps to be added later. As far as multiple small caps versus fewer large ones it's up to you. Wiring up 20 or more small caps on each supply rail can get old in a hurry and I'm not sure that you would end up with better performance in the end. Using the large caps and the PS board from the store will give you a good solid supply that will be easy to assemble, mount and service if needed.
I'm not sure about capacitor brands but I do know that there seem to be a lot of fake electrolytic caps for sale on Ebay. If you see a cap for sale on Ebay, look up the manufacturers specs for a cap of that series and size. In most cases you can't find them listed on the manufacturers site. Buy your capacitors from Mouser or Digikey or some other legit. business. Review the specs and pick the ones that match your needs and fit within your budget. Have fun with the project and know that if you stick to the proven formula you will end up with a world class amplifier. After you get a taste of the sound then look for exotic parts if you feel the need. There is lots of help here if you run into any trouble with the build.
As far as fuses go, if you use the CL60 surge suppressors in the primary of the transformer you shouldn't need to worry about blowing fuses. The recommended fuse size should work fine. Again, if you are unsure, stick with the recommended formula and all should be fine.
I would recommend using a larger transformer than 300va. There seems to be a lack of standards in rating transformers. I used a 400va Antek 20v x2 transformer for my Aleph. With slightly more than the recommended bias it runs pretty warm but not hot. I can vouch for this transformer working well for an Aleph J and will give you close to 24volt rails. I wouldn't go any lower than that size, at least within the Antek line.
With an Aleph J you are usually limited to your heatsink size for turning up the bias. Therefore you really can't get much extra output power from a really large transformer. The 400va Antek also comes with a electrostatic shield and a core band to lower the magnetic field. That will generally mean fewer problems with hum. Some of the larger sizes do not have these features so that is also something to consider.
As far as capacitors go, more is better up to a point. Because an Aleph is single ended you can't get the large peak output currents you will get with a push pull amp like an F5. So, the cap setup recommended by 6L6 is certainly enough for starters. If you think you may want more then leave space in the chassis for more caps to be added later. As far as multiple small caps versus fewer large ones it's up to you. Wiring up 20 or more small caps on each supply rail can get old in a hurry and I'm not sure that you would end up with better performance in the end. Using the large caps and the PS board from the store will give you a good solid supply that will be easy to assemble, mount and service if needed.
I'm not sure about capacitor brands but I do know that there seem to be a lot of fake electrolytic caps for sale on Ebay. If you see a cap for sale on Ebay, look up the manufacturers specs for a cap of that series and size. In most cases you can't find them listed on the manufacturers site. Buy your capacitors from Mouser or Digikey or some other legit. business. Review the specs and pick the ones that match your needs and fit within your budget. Have fun with the project and know that if you stick to the proven formula you will end up with a world class amplifier. After you get a taste of the sound then look for exotic parts if you feel the need. There is lots of help here if you run into any trouble with the build.
As far as fuses go, if you use the CL60 surge suppressors in the primary of the transformer you shouldn't need to worry about blowing fuses. The recommended fuse size should work fine. Again, if you are unsure, stick with the recommended formula and all should be fine.
Thank you Bfbca and Dennis for the advices and recommendation. In this case, I will go with 400 VA Antek transformer since it has electrostatic shield and go all full for the RC caps at 88000uF per rail.
It's a bit confusing to me. In the PSU schematic, it says use 2.5A 3AG slow blow fuse at 120V and in the Alelph J manual, it mentions 3AG slow blow, 4A (120VAC). 2.5A and 4A is a big difference!
Thanks,
Tom
It's a bit confusing to me. In the PSU schematic, it says use 2.5A 3AG slow blow fuse at 120V and in the Alelph J manual, it mentions 3AG slow blow, 4A (120VAC). 2.5A and 4A is a big difference!
Thanks,
Tom
I do not follow the manual but tend to use the fuse size recommended in the toroid datasheet. Amplimo specifies which size to use. Not sure if others do so too.
Chassis for Aleph J
Hi All,
I was wondering if using the Dissipante 4U would be ok? The dimensions look the same, and if I substituted the UMS heatsinks and the delux back panel it would be $100 cheaper than the Delux 4U aluminum chassis. I know it's not as trick looking as the aluminum panels but I actually like the black front better. The $100 saved would also offset any import taxes etc for the delivery to Canada. Any thoughts, as always, would be greatly appreciated!
Thanks!
Hi All,
I was wondering if using the Dissipante 4U would be ok? The dimensions look the same, and if I substituted the UMS heatsinks and the delux back panel it would be $100 cheaper than the Delux 4U aluminum chassis. I know it's not as trick looking as the aluminum panels but I actually like the black front better. The $100 saved would also offset any import taxes etc for the delivery to Canada. Any thoughts, as always, would be greatly appreciated!
Thanks!
If the heat sinks are the same size as the delux and you can fit the amp circuits, power supply inside, it will work. Heat sinks are almost always aluminum. In this case, they are aluminum. The steel will be a bit heavier and a little hard to machine or drill, but it will work.
You didn't ask, but I'll tell you anyway, try lifting the transformer .75 to 1 inch off the chassis base. Use a non-magnitic material. I heard about this a while ago and it works wonders. I tried it in DACs, preamps and amps. Results are always good. Don't cost much and easy to test and put back to normal position. I would definitely do this on a steel chassis. Just my two cents.
It will certainly do the job since the heatsinks are the same. You will be surprised at how cheap the shipping is to Canada on those store chassis. They provide free shipping to USA and only charge the difference to Canada.
Check to see if there is any duty to be paid when importing the chassis from Italy. You don't want any surprises.